Gaseous transfer in multiple metal bath reactors

ABSTRACT

An economically viable and environmentally sound process is described for the transformation of solid, liquid, gaseous and related hydrocarbon feedstocks into high purity, high pressure gas streams that may be further processed in conjoined multiple metal bath reactors.

RELATED APPLICATIONS SECTION

This application claims the benefit to US Provisional Patent ApplicationNo. 61/025,684, filed on Feb. 1, 2008. The entire teaching of the aboveapplication is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention describes a method for the production of highpurity, high pressure gas streams comprising methane (CH₄), syngas(CO/H₂) and hydrogen (H₂). The method advantageously can be used toproduce large volumes of these gaseous products at a lower cost thancurrently now available by prior art methods. The methane gas stream canbe used as a fuel or energy source and/or as a building block to producea number of higher molecular weight hydrocarbons. The hydrogen gas canbe used in a variety of applications including but not limited to thereduction of carbon dissolved in liquid metals, H₂ storage in fuelcells, and hydrogenation reactions. In one embodiment, the syngas(CO/H₂) can be delivered in a 1:1 ratio under high pressure and highpurity for use in very diverse chemical transformations such as theFischer-Tropsch reaction.

BACKGROUND OF THE INVENTION

It is now well established that there is a worldwide energy shortage andparticular emphasis has been placed upon new technologies for theconversion of our naturally abundant resources such as coal to morebroadly useful gaseous materials such as syngas (CO/H₂), hydrogen (H₂),methane (CH₄) and other low molecular weight hydrocarbons. Additionally,the economical production of natural gas and high-value energy sourcesthat can be used in place of natural gas has become an economicnecessity. Natural gas has a composition that includes about 80-85percent methane (CH₄), about 10 percent ethane (C₂H₆) with varyingpercentages of higher hydrocarbons including propane (C₃H₈) and butane(C₄H₁₀). The primary component of natural gas, methane, has a heatingvalue of about 23,875 Btu/lb.

There are particular advantages to natural gas and other high BTU gascompositions being produced on site and utilized in such energyconsuming applications as the production of electricity. Although thecombustion of coal to generate steam, can be used to generateelectricity, coal deposits frequently contain high levels of impuritiessuch as sulfur and mercury and consequently must be subjected toexpensive processing prior to utilization. Thus, the direct conversionof the carbon in the coal to a hydrocarbon product of high purity, suchas methane gas, remains a highly desirable objective. Many processescurrently available have not proven to be economic. New processes thatare both highly economical and ecologically sound must be developed tosatisfy current energy and raw material demands that can potentially uselow-grade coal sources.

In marked contrast to coal gasification, incineration typically involvesa combination of pyrolysis (1200° C.) and combustion that is initiatedby a high temperature flame. At such high temperatures, pyrolysistransforms organic compounds into a more oxidizable form, but theoxidation step requires the actual collision of the resulting incipienthigh-energy carbonaceous fragments with oxygen. Lack of efficient mixingon a molecular level impedes the rate of oxidation. Alternatively, moremodern methods of coal gasification are initiated at high temperaturesbut the coal is injected into hot molten metal baths for the purpose ofthermal decomposition into molecular fragments followed by certain otherchemical transformations of the atomic carbon into usable gaseousspecies.

In Rummel's U.S. Pat. No. 2,647,045, for example, a molten slag bathobtained from the reduction of iron ore or from the “non-combustibleresidues of coal products” is circulated and finally divided coal isinjected into the bath and a separate addition of air is also conductedalong with “an endothermic gaseous reactant”, e.g. water and CO₂. U.S.Pat. No. 3,700,584 by Johanson treats low quality coal having a highoxygen content in a gasification process converting the coal to a usefulhydrocarbon product.

An iron bath is used for coal gasification in U.S. Pat. No. 4,388,084.In U.S. Pat. No. 4,389,246 issued to Okamura et al., on the subject ofcoal gasification employing a molten iron bath, the bottom-blowing ofethane is described. The ethane or other hydrocarbon gas is used to stirthe mixture and is considered by Okamura et. al. to be equivalent tooxidizing gases. Injection from above is employed in Gernhardt et. al.,U.S. Pat. No. 4,043,766; Okamura et. al. U.S. Pat. No. 4,389,246: Okaneet. al. U.S. Pat. No. 4,388,084; and Bell et. al. U.S. Pat. No.4,431,612.

Other processes for producing synthesis gas from steam and carbon havebeen disclosed. For example, U.S. Pat. No. 1,592,861 by Leonarzdescribes a method for the production of water gas by contacting steamwith uncombined carbon in a bath of molten metal. The steam isdissociated into its respective elements at temperatures of 900° C. to1200° C. The carbon combined with the oxygen of the gas is sufficient inquantity to produce carbon monoxide but not to make an appreciablequantity of carbon dioxide.

Molten iron is employed by Rasor in U.S. Pat. Nos. 4,187,672 and4,244,180 as a solvent for carbon generated through the topsideintroduction of coal; the carbon is then partially oxidized by ironoxide during a long residence time and partially through theintroduction of oxygen from above. For example, raw coal can be gasifiedin a molten metal bath such as molten iron at temperatures of 1200° C.to 1700° C. Steam is injected to react with the carbon endothermicallyand moderate the reaction. The Rasor disclosure maintains distinctcarbonization and oxidation chambers.

Bach et.al. in U.S. Pat. Nos. 4,574,714 and 4,602,574 describe a processfor the destruction of organic wastes by injecting them, together withoxygen, into a metal or slag bath such as is utilized in a steelmakingfacility. Nagel et.al. in U.S. Pat. Nos. 5,322,547 and 5,358,549describe directing an organic waste into a molten metal bath, includinga first reducing agent which chemically reduces a metal of themetal-containing component to form a dissolved intermediate. A secondreducing agent is directed into the molten metal bath. The secondreducing agent, under the operations of the molten metal bath,chemically reduces the metal of the dissolved intermediate, thereby,indirectly chemically reducing the metal component of the waste.

Hydrogen gas (H₂) can be produced from feedstocks such as natural gas,biomass and water (steam) using a number of different technique. U.S.Pat. No. 4,388,084 by Okane et al. discloses a process for thegasification of coal by injecting coal, oxygen and steam onto molteniron at a temperature of about 1500° C. The manufacture of hydrogen bythe reduction of steam using an oxidizable metal species is also known.For example, U.S. Pat. No. 4,343,624 by Belke et. al., discloses athree-stage hydrogen production method and apparatus utilizing a steamoxidation process. U.S. Pat. No. 5,645,615 by Malone et al. discloses amethod for decomposing carbon and hydrogen containing feeds, such ascoal, by injecting the feed into a molten metal using a submerged lance.Malone et. al. in U.S. Pat. No. 6,110,239 describe a hydrocarbongasification process producing hydrogen-rich and carbon monoxide-richgas streams operating at pressures above 5 atmospheres where the moltenmetal is transferred to different zones within the same reactor effectedby vertical baffles for the purpose of modulating carbon concentrations.

The method of Kindig et.al. in U.S. Pat. Nos. 6,682,714; 6,685,754 and6,663,681 describes the production of hydrogen gas, formed by steamreduction using a metal/metal oxide couple to separate oxygen from H₂O.The method utilizes one of the fundamental operations of Nagel et.al.,U.S. Pat. No. 5,358,549 that reduces a dissolved metal oxide with acarbon source such as CO or coal. Steam is contacted with a molten metalmixture including a first reactive metal such as iron dissolved in adiluent metal such as tin. The reactive metal oxidizes to a metal oxide,forming a hydrogen gas and the metal oxide can then be reduced back tothe metal for further production of H₂ without substantial movement ofthe metal or metal oxide to a second reactor. It is suggested thatpreventing the physical movement of such nongaseous materials such as Feand FeO, on a commercially useful scale involving several hundred tonsof material, may reduce the cost associated with the production ofhydrogen gas. Kindig et.al. (U.S. Pat. No. 7,335,320) produces ahydrogen-containing synthesis gas (H₂:CO) in a 1:1 molar ratio usingseveral hundred tons of material without the need to remove carbonoxides from the gas stream.

A number of metal/metal oxide systems have been used in addition toiron/iron oxide. For example, U.S. Pat. No. 3,821,362 by Spacilillustrates the use of Sn/SnO₂ to form hydrogen. Molten tin is atomizedand contacted with steam to form SnO₂ and H₂; the SnO₂ is reduced backto liquid tin.

Davis et.al. in U. S. Publication. No. 20060228294 (European PatentEP1874453) have described a process and apparatus for treating organicand inorganic waste materials in a high temperature metal bath reactorto produce syngas by the reaction of steam with iron metal. However,this process requires injecting oxygen, steam and/or co-feeding one ormore additional feed materials of higher heat value in order to maintaina balanced production of syngas.

In spite of the above mentioned processes, however, a more efficientmethod of producing syngas at high pressure and high temperature remainsa desirable goal.

SUMMARY OF THE INVENTION

In one embodiment, the invention relates to a reactor system capable ofwithstanding high temperatures and high pressures. The reactor systemcan possess one or more reactive chambers and can be used in processesentailing one or more steps.

In one embodiment, the process includes injection of a hydrocarbonfeedstock, such as coal, into a first, high temperature liquid metalbath (such as a chamber of a reactor described herein), therebyproviding an opportunity for specific chemical operations that providevaluable products such as methane (CH₄), syngas (CO/H₂), H₂, CO andhigher hydrocarbons under pressures up to 200 bar or more and/orpurities of 99% or more by weight. The off gases produced in this firstbath, such as CO, CO₂, H₂S, H₂ and N₂, can be transferred to a secondarymolten metal bath (e.g., in the same or different reactor) and can befurther processed. Impurities can be removed as slag or in gaseous formin the lower bath. Reduction chemistry can take place in another metalbath, such as a conjoined upper bath. Carbon dissolved in the first, orprimary, metal bath, may be transferred (e.g., vertically orhorizontally, for example, under a pressure differential or bymechanical means), to a second, preferably upper, bath for a reductionreaction, such as reduction of carbon to produce purified methane, orwater to produce CO and/or H₂ under high pressure. Metal transfer ratesbetween conjoined baths can be controlled by releasing or buildingpressure using the exit gas control valves and or by adjusting feedstockinjection rates. Oxidation of the metal in a metal oxide-rich adjoiningupper liquid metal bath, free from impurities, with steam, provides apure high pressure stream of syngas in a stoichiometric 1:1 ratio(CO/H2). This multiple conjoined metal bath technology can remediate avariety of different hydrocarbon materials affording high purity, highpressure gaseous products in addition to saleable byproducts includingbut not limited to H₂SO₄ and CO₂.

One preferred embodiment of the present invention describes a process inwhich high-purity, and optionally, high-pressure syngas (CO/H₂) or H₂gas streams and/or a high-purity, high-pressure “carbon containing” gasstream are alternatively, independently and/or simultaneously producedseparately and, preferably, continuously from a molten metal bath thatcontains multiple zones. The term “high-purity” syngas or H₂ gas means agas stream that contains at least about 99% by weight CO and/or H₂,preferably at least about 99.5%. Purity levels of about 99.9% by weighthave been achieved in accordance with the inventions described herein.The term “high-purity” carbon-containing gas stream means a gas streamthat contains at least about 99% by weight carbon containing compounds,e.g., hydrocarbons (preferably methane, and/or other C₁-C₄hydrocarbons), and preferably at least about 99.5% by weight carboncontaining compounds, e.g., preferably at least about 99.5% by weightmethane. Again, purities of about 99.9% methane by weight can beachieved.

The gaseous streams produced by the processes described herein can beobtained at high pressure. Of course, the pressure of the gas can bereduced or, alternatively, the pressure can be further increased or thestream can be liquefied. The term “high-pressure” syngas or H₂ gas, whenreferring to the gas stream exiting the process, means a gas stream thathas a pressure of at least about 1 bar, preferably at least about 10bar, or most preferably at least about 100 bar. The reactor canpreferably accommodate pressures of up to about 600 bar, such as betweenabout 150 bar and 200 bar.

DESCRIPTION OF THE DRAWING

FIG. 1 is a conceptual view of an example of a metal bath reactor of thepresent invention.

FIG. 2 is a conceptual view of another example of a novel molten metalcontainment vessel.

FIG. 3 is a schematic representation of a series of molten metal bathsthat can be juxtaposed in both horizontal and vertical positions thatconstitute an overall reactor for conducting the method of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

The features and other details of the method of the invention will nowbe more particularly described with reference to the accompanying FIG. 3and pointed out in the claims. It will be understood that particularembodiments of the invention are shown by way of illustration and not aslimitations of the invention. The principal features of this inventioncan be employed in various embodiments without departing from the scopeof the invention.

In one embodiment, the invention relates to a reactor system capable ofwithstanding high temperatures and high pressures comprising:

-   -   a. a first bath vessel capable of containing a bath having a        bath temperature, T1, and a bath vessel pressure, P1; and    -   b. a reactor housing characterized by a housing temperature,        T10,        Wherein the first bath vessel is contained within the housing        and having a gas zone having a gas zone pressure, P10, disposed        therebetween and wherein P10 approximately the same as P1 and        T10 is less than T1. More than one bath vessel (e.g., two,        three, four or more) can be included within one, two or more        reactor housings.

In another embodiment, the invention includes a reactor systemcomprising:

-   -   a. a first bath vessel capable of containing a metal bath having        a bath temperature, T1 and a bath pressure P1;    -   b. a second bath vessel capable of containing a bath having a        bath temperature, T2 and a bath vessel pressure P2 disposed        above said first bath vessel;    -   c. a first conduit in fluid communication with the first bath        vessel and second bath vessel, whereby the pressure difference        between P2 and P1 causes transfer of a liquid residing in said        first bath vessel to said second bath vessel; and    -   d. a second conduit in fluid communication with the first bath        vessel and second bath vessel, whereby gravity causes transfer        of a liquid metal residing in said second bath vessel to said        first bath vessel.

The bath vessels of molten metal reactors, including but not limited tothe reactors described herein, contain a molten metal bath, as describedin more detail below. Generally, the molten metal bath contains areactive species, such as iron/iron oxides and/or nickel. The reactivespecies, such as iron, can be added and maintained as a solid, e.g.,iron filings and need not be molten per se. It has been found that thedensity of the molten metal bath can be advantageously approximated tothe density of the reactive species, thereby retaining the solidreactive species in substantial suspension. This can be achieved byoptimizing the alloy components of the bath and temperature and hencethe melting point of the bath. Maintaining the reactive species insuspension permits lower reaction temperatures, improves reaction times,and avoids loss due to layering.

Bath temperatures (T1, T2, T3 T4, etc.) are generally greater than about200 F and are preferably greater than about 500 F and can be up to about1000 F or about 3000 F or more. The reactor housing temperatures, on theother hand, are generally substantially less than the bath vesseltemperatures and can be between room temperature (or below) and about500 F. The difference in the bath temperature(s) and housingtemperature(s) can be, for example, at least about 100 F, preferably atleast about 200 F and more preferably greater than about 300 F.

Bath vessel pressures are substantially the same as the gas zonepressures surrounding the bath vessel. The pressures are considered tobe substantially the same if the pressures are within about 10%, forexample within about 5%. Preferably, the gas zone pressure is slightlygreater (e.g., about 1%) than the bath vessel pressures. The bath vesselpressures are preferably at least about 1 bar, e.g., greater than 5 bar,such as greater than about 10 bar or about 100 bar. Pressures of 600 baror more can be achieved. Preferably, the bath vessel pressures arebetween about 150 and 200 bar.

The gas zone within the reactor housing enclosing the bath vessel ispreferably filled with a gas, such as an inert gas. Suitable gasesinclude air, carbon dioxide and argon. Carbon dioxide is preferred.Argon can be used when it is important to use an inert gas (e.g., thereactor housing is equipped with induction coils). The gas can be chosento provide good insulation properties.

Each bath vessel is preferably made of a material that can withstand amolten metal bath and, preferably, has a tensile strength of at least50,000 psi, preferably at least about 100,000 psi. For example, a 5 inchthick stainless steel vessel or a graphite vessel can be used. Thevessel can be optionally lined with a refractory material, asappropriate.

The reactor system can optionally comprise a second or third or morebath vessel within each housing. In one embodiment, the second bathvessel is disposed vertically above the first bath vessel, although ahorizontal arrangement of the vessels is possible as well. Where thebath vessels are arranged vertically, the vessels can be separated by aplate, such as a stainless steel plate coupled to the reactor housing.The vessels are preferably sealed, e.g. with a compression seal, by theplate.

The liquid baths of at least two vessels are preferably in liquidcommunication. In one embodiment, the bath vessel pressure in the second(or upper) bath vessel, P2, is lower than bath vessel pressure of thefirst, or lower, bath vessel, P1. This provides a pressure differentialthat can lift or transport the liquid in the lower bath to the upperbath without the assistance of mechanical means. Of course, the transferof liquid between bath vessels can be achieved, or assisted,mechanically as well.

In this embodiment, the reactor system further comprising a firstconduit in fluid communication with the second bath vessel and firstbath vessel, whereby the pressure difference between P1 and P2 causestransfer of a molten metal residing in said first bath vessel to saidsecond bath vessel. The first conduit preferably comprises an inletdisposed in the lower half of the first bath vessel and an outletdisposed in the upper half of the second bath vessel. Preferably, thefirst conduit comprises a first valve to control molten metal transfer.

The reactor system alternatively or additionally comprises a secondconduit in fluid communication with the second bath vessel and firstbath vessel, whereby gravity causes transfer of a molten metal bathresiding in said upper second bath vessel to said first bath vessel. Thesecond conduit preferably comprises an inlet disposed in the lower halfof the second bath vessel and an outlet disposed in the upper half ofthe first bath vessel. The second conduit can include a second valve(e.g., a ball valve) to control molten metal transfer. Where both firstand second conduits are present, bidirectional flow between the bathvessels can be achieved.

The reactor system is preferably equipped with appropriate inlets andoutlets. For example, each bath vessel can be characterized by at leastone gas exhaust port, at least one steam inlet port, at least onefeedstock inlet port, at least one gas steam inlet port and/or a slagremoval port. The inlet ports can be located above, or preferably below,the surface of the molten metal in each bath vessel and can includetuyere injection. Gas exhaust ports are generally located in the headspace of the reactor. A slag removal port is generally locatedapproximately at the surface level of the liquid bath.

The vessels can further contain baffles, plates or other means fordirecting the flow of the feed, gases and/or molten metals within thebath to control residence times.

The reactor system can comprise a plurality of the reactors discussedabove. In this embodiment, the reactor system can further comprise, forexample:

-   -   a. a third bath vessel capable of containing a molten metal bath        having a bath temperature, T3 and a bath pressure P3;    -   b. a fourth bath vessel capable of containing a molten metal        bath having a bath temperature, T4 and a bath vessel pressure P4        disposed above said third bath vessel;    -   c. a second reactor housing characterized by a housing        temperature, T11, wherein the third bath vessel is contained        within the second reactor housing and having a gas zone having a        gas zone pressure, P11, disposed therebetween and wherein P11        approximately the same as P3 and T11 is less than T3;    -   d. a third conduit in fluid communication with the third bath        vessel and fourth bath vessel, whereby the pressure difference        between P3 and P4 causes transfer of a molten metal residing in        said third bath vessel to said upper fourth bath vessel and        wherein the third conduit comprises an inlet disposed in the        lower half of the third bath vessel and an outlet disposed in        the upper half of the fourth bath vessel;    -   e. a fourth conduit in fluid communication with the third bath        vessel and fourth bath vessel, whereby gravity causes transfer        of a molten metal bath residing in said fourth bath vessel to        said third bath vessel; wherein the fourth conduit comprises an        inlet disposed in the lower half of the fourth bath vessel and        an outlet disposed in the upper half of the third bath vessel.

The multiple reactor housing can be separate and distinct or conjoined,e.g. as a quad configured reactor with four bath vessels. Otherarrangements can be envisioned as well.

Referring to FIGS. 1 and 2, FIG. 1 is a conceptual view of an example ofa liquid metal, or molten metal bath system generally denoted by thenumeral 10. In the example of FIG. 1 system 10 includes a first chamber12 and a second chamber 14 disposed within a reactor housing 16. System10 may include one, two or more chambers. Additionally, multiplechambers of system 10 may be incorporated into one or more separatevessels generally referred to herein as reactors.

For purposes of description, system 10 is utilized to process solid,liquid and gaseous elements from a feedstock. The feedstock is injectedinto a high temperature liquid metal bath 18 where the elements aredisassociated into their atomic constituents. Multiple liquid metalbaths operating at high pressure allow for further partitioning ofelements and compounds for significant advantages. Therefore, a systemthat facilitates the transfer of the liquid metal from one chamber orbath to another facilitates advantages.

For purposes of explanation, first chamber 12 is provided herein as theprimary or initial reactor bath. The feedstock is injected into moltenmetal 18 contained within first chamber or bath 12. Molten metal 18 istransferred to second chamber or bath 14 for further processing viamolten metal transfer system generally denoted by the numeral 20. Moltenmetal 18 may be further transferred to additional chambers or back toprimary chamber 12.

Various means and mechanisms for transfer of molten metal 18 may beutilized. One example of transfer system 20 is described herein and isadapted to transfer molten metal 18 horizontally or vertically. In theillustrated example, transfer system 20 utilizes pressure differential.For example, molten metal 18 a is positioned in chamber 12 and moltenmetal 18 b is positioned in chamber 14 which in this example iselevationally, or in terms of pressure head, above chamber 12. Liquidmetal transfer system 20 includes piping 22 and control unit 24. Piping22 provides one or more fluid paths between chambers 12 and 14. In thisexample, conduit 22 a provides a path from chamber 12 to chamber 14 andconduit 22 b provides a path from chamber 14 to chamber 12. Control unit24 is functionally and operationally connected to one or more dischargeports 26 a, 26 b and chambers 12 and 14. Utilizing pressuredifferentials, and regulation of feed and discharge from chambers 12 and14, controller 24 can provide the desired movement of metal 18 throughthe various chambers.

Another aspect of the present system is the provision of a novel thermalbarrier vessel design. Refer now to FIG. 2, wherein a conceptual view ofa single chamber reactor 16 is illustrated. Reactor 16 includes an innervessel 26 and an outer vessel 28. Positioned between inner vessel 26 andouter vessel 28 is a fluid thermal barrier material 30. In the presentexamples, thermal barrier material 30 is either a liquid or gas. Oneexample of a thermal barrier material 30 is argon.

The inner vessel 26 may be at a pressure such as 160 bar. Thermal fluidbarrier 30, such as argon, may be contained between vessel 26 and 28 ata pressure proximate to or higher than the pressure inside of the innervessel. Thermal barrier 30 facilitates shielding outer vessel 30 fromthe internal temperatures and provides a pressure containment means.

The reactor system can advantageously be used in multi stage reactions.For example, each bath vessel can be characterized by a head space andthe head space of the first bath vessel is in fluid communication withthe molten metal bath of another bath vessel, e.g., the third bathvessel; the head space of the fourth bath vessel is in fluidcommunication with another bath vessel, e.g., the second bath vessel.Additional vessels can be incorporated within the housing, above, below,between or next to the first and/or second bath vessel. For example, aheat exchanger can be incorporated to assist in optimizing thedispersion of heat generated in a bath. Various combinations can beeasily envisioned.

The reactor systems can be used to manufacture high purity, highpressure gas streams, and other products.

Another aspect of the invention includes processes of manufacturing highpurity, high pressure gas streams, which preferably (but is notnecessarily limited to) using the reactors described herein. In oneembodiment of the invention a process for making a high purity methanegas comprises the steps of:

-   -   a. Adding a carbon-containing feed stream into a first bath        vessel containing a first molten metal bath wherein the first        bath vessel is maintained at a pressure, P1, of at least 1 bar,        preferably at least 100 bar, and producing a first vessel gas        stream comprising carbon monoxide and hydrogen sulfide;    -   b. Removing the first vessel gas stream from the first bath        vessel and introducing the gas stream into a third bath vessel        containing a third molten metal bath wherein the third bath        vessel is maintained at a third pressure, P3, of at least 1 bar,        preferably at least 100 bar, optionally adding an oxygen source,        such as steam or an oxygen containing feed, and producing a        third vessel gas stream comprising hydrogen, SO₃ and carbon        dioxide;    -   c. Removing the third vessel gas stream from the third vessel,        and optionally condensing the SO₃ therefrom and/or removing the        carbon dioxide; thereby obtaining a purified high pressure        hydrogen gas;    -   d. Adding steam to a fourth bath vessel containing a fourth        molten metal bath characterized by a low carbon content, wherein        the fourth bath vessel is maintained at a fourth pressure, P4,        of at least 1 bar, preferably at least 100 bar, thereby        producing purified hydrogen;    -   e. Adding the gas streams produced by step (c) and/or (d) to        second upper bath vessel containing a second molten metal bath        maintained at a second pressure, P2, of at least 1 bar,        preferably at least 100 bar, and a temperature of less than        about 1000 F, preferably about 800 F characterized by a high        carbon content, thereby producing purified methane.        In another aspect, a process for making a high purity syngas        comprises the steps of:    -   a. Adding a carbon-containing feed stream into a first bath        vessel containing a first molten metal bath wherein the first        bath vessel is maintained at a pressure, P1, of at least 1 bar,        preferably at least 100 bar, and producing a first vessel gas        stream comprising carbon monoxide and hydrogen sulfide;    -   b. Removing the first vessel gas stream from the first bath        vessel and introducing the gas stream into a third bath vessel        containing a third molten metal bath wherein the third bath        vessel is maintained at a third pressure, P3, of at least 1 bar,        preferably at least 100 bar, optionally adding an oxygen source        to maintain a metal oxide rich bath environment, such as steam        or an oxygen containing feed, and producing a third vessel gas        stream comprising hydrogen, SO₃ and carbon dioxide;    -   c. Removing the third vessel gas stream from the third vessel,        and optionally condensing the SO₃ therefrom and/or removing the        carbon dioxide; thereby obtaining a purified hydrogen gas;    -   d. Adding steam to a fourth bath vessel containing a fourth        molten metal bath characterized by a low carbon content, wherein        the fourth bath vessel is maintained at a fourth pressure, P4 ,        of at least 1 bar, preferably at least 100 bar, thereby        producing purified hydrogen;    -   e. Adding oxygen gas to a second bath vessel containing a second        molten metal bath maintained at a second pressure, P2, of at        least 1 bar, preferably at least 100 bar, and a temperature of        less than about 1000 F, characterized by a high carbon content,        thereby producing purified carbon monoxide.        In yet another embodiment, a process for making a high purity        hydrogen gas comprises the steps of:    -   a. Adding a carbon-containing feed stream into a first bath        vessel containing a first molten metal bath wherein the first        bath vessel is maintained at a pressure, P1, of at least 1 bar,        preferably at least 100 bar, and producing a carbon rich molten        metal bath;    -   b. Transferring the carbon rich molten metal bath to a second        upper bath vessel; maintained at a second pressure, P2, of at        least 1 bar, preferably at least 100 bar, and a temperature of        less than about 1000 F;    -   c. Adding steam to the carbon rich molten metal bath thereby        producing a high purity hydrogen gas.        These processes can use one or more reactors as described above,        such as a dual conjoined reactor or a pair of dual conjoined        reactors.

The processes contemplate employing molten metal baths. The molten metalbaths can comprise a number of metal species and can include reactive ornon reactive species. The reactive species are preferably those thatundergo oxidation/reduction reactions. Nickel and iron can be selectedwith iron being preferred. Of course, the reactive species need not bemolten itself. In one embodiment, the reactive species can be added andmaintained as a solid, for example, in the form of iron filings. Themolten metal bath can be selected to have substantially the same densityof the solid reactive species to facilitate suspension and avoidlayering in the bath. In one embodiment, the molten metal baths can beselected to facilitate purified carbon transport between vessels (e.g.,between the first and second vessel of the methane or syngas productionsystem). One preferred bath for the first and second vessels can be aSn/Pb alloy having iron filings suspended therein.

The metal baths can also include antimony (Sb), Cobalt (Co) germanium(Ge), indium (In), molybdenum (Mo), lead (Pb) tungsten (W), bismuth(Bi), cadmium (Cd), copper (Cu), gold (Au), iridium (Ir), mercury (Hg),nickel (Ni), osmium (Os), platinum (Pt), rhenium (Re), rhodium (Rh),ruthenium (Ru), selenium (Se) and/or tellurium (Te).

The feedstock used in the processes are generally carbon containing andare preferably hydrocarbon-containing feedstocks. Suitable feedstocksinclude comprises a coal, petroleum coke, coal, lignite coal, oil shale,natural gas or biomass, liquid or gaseous hydrocarbons (e.g., methane,ethane and the like). Waste materials, such as wastes having a thermalcontent of at least about 4,000 BTU per pound can also be used.Combinations of feedstocks can be selected to provide an improved oroptimal carbon, oxygen, water balance.

The feedstock can be added by several means, including but not limitedto auger extrusion, bottom or side injection or by steam-cooled toplance injection.

As discussed above with respect to the reactors, the pressures in atleast one, two, three, four or all bath vessels can be maintained atpressures of at least about 1 bar, such as at least about 10 bar ormore, e.g., between 1 (or 10) and about 600 bar. Preferably the pressureis maintained in the range between about 150-200 bar. The reactor, orvessel(s), pressures can be controlled or maintained by the hydrocarbonfeedstock addition rate(s).

The inventions relate to the discovery that that molten metal baths canbe transported easily between bath vessels (such as vertically alignedbath vessels) by maintaining a pressure differential greater than thepressure required to lift the metal and overcome resistance in metaltransfer piping in a vertical and/or a diagonal direction. This featureis discussed in more detail with respect to the reactors.

In the conversion of a hydrogen disulfide, carbon monoxide and/or water,(as illustrated herein in the third and fourth bath vessels) the bathsare preferably maintained at a temperature at least greater than themelting point of the metal or alloy (e.g., 1000° F.) and generally notgreater than about 3000° F. (e.g., between about 2000° F. and 3000° F.).In general, the bath used in the conversion of carbon to methane is notgreater than 800-1000° F. As such, the conversion of the feedstock tocarbon monoxide and carbon in the first bath vessel is also generallynot greater than 1000 F.

The processes described herein often employ feedstocks that containcertain amounts of impurities, such as heavy metals and mercury. Many ofthe heavy metals are removed from the process in the slag layer in thefirst vessel. Mercury, however, is often removed in the gas streamremoved from the first vessel. In one embodiment, the invention furthercomprises a step of extracting Hg before it enters the third bath vesselor even after it exits the third bath vessel in the bath vessel gasstream.

Likewise, hydrocarbon feedstocks generally contain sulfur. Adding thehydrocarbon feedstock to a molten metal bath generally converts sulfurto hydrogen sulfide (e.g., in the first bath vessel). Adding oxygen to amolten metal bath (e.g., in the third bath vessel) to maintain a metaloxide rich bath can result in the conversion of the hydrogen sulfide toSO₃, which is then removed in the off gas stream exiting the third bathvessel. The invention contemplates the additional step of extracting theSO₃ from this off gas stream by quenching with water to produce H₂SO₄, avery useful saleble product.

High pressure carbon dioxide is also produced in the third bath vessel.The method contemplates the optional step of the separating CO₂ in theoff gas stream of the lower bath of the second set of vertical baths.The carbon dioxide and can be used in further applications and can beobtained as a supercritical fluid. A supercritical, or other highpressure, CO₂ gas stream can be used for direct CO₂ pipeline injectionfor enhanced oil recovery. Can be sequestered into a saline aquifer.

A method of claim 1 comprising the step of oxidizing dissolved carbon inthe first upper molten metal bath with water to produce CO+H₂.

The processes described herein employ several chemistries. For example,the process contemplates recycling recovered H₂ from the off gas streamof the upper bath of the second set of vertical baths back to the upperfirst bath as a reducing gas for the production of methane andhomologous hydrocarbons by oxidizing the reactive bath metal (e.g. Fe)with steam to produce metal oxide and hydrogen gas.

As described above, the process contemplates producing a slag layer. Theslag layer assists in removing impurities and controlling dust and ash.The processes of the invention can therefore comprise the step offorming a slag layer by addition of a flux consisting of typical oxidesof Ca, Fe, K, Mg, Na, Si, Sn, Ti and the like.

Maintaining a pressure balance between the two, three, four or more bathvessels can optimize the efficiency of the system and the processesdescribed herein, For example, in the four vessel system describedherein, maintaining the relative pressures such that the pressure infirst bath vessel such that it is usually or always greater than that inthe third bath vessel, which in turn is generally maintained at a higherpressure than the fourth bath vessel, which, in turn, is generallymaintained at a higher pressure than the second bath vessel. Thisconfiguration allows optimal transfer of gaseous materials between allbaths without the need for gas compression. Where the vessels are alsomaintained as a pair of vertically disposed vessels, the arrangementpermits good molten metal transfer between the pairs of vessels as well.

In one embodiment, H₂ reduction of atomic carbon to hydrocarbons using amolten metal catalyst, instead of a solid support catalyst, increasesthe overall catalyst surface area while reducing the structuralrequirements for providing a comparable solid catalyst surface area andreducing the potential for solid catalyst meltdown from the excessivetemperatures that are required to get comparable yields of hydrocarbon.

It is understood that, with respect to the above processes, that not allsteps are required in all applications and/or that one step can bereplaced by an equivalent process step. Thus, the inventions includeprocessed that are characterized by one, two, three, four, all of thedelineated steps set forth above. In some embodiments, the bath vesselin which the hydrocarbon feedstock(s) are introduced can also bemodified. Thus, while the specifically described processes generallyrefer to the addition of the feedstock into the first bath vessel, it ispossible that feedstock can be added to any other bath vessel.

One may use two dual bath reactors or a quad configuration for thedirect production of synthetic natural gas (SNG) or pure methane. In oneversion of the invention, a high concentration of carbon containingfragments (e.g., a feedstock having, for example, at least 15% by weightof carbon), is transferred to an adjoined molten reactor. The steps ofsuch a process may comprise (a) introducing a hydrocarbon feed into afirst molten metal bath (such as, a “primary Sn bath”) by, for example,bottom injection at an operating pressure of 150-200 bar causingdecomposition of the hydrocarbon feed into hydrogen and carboncontaining fragments that dissolve or suspend in the molten metal baththereby increasing the overall net carbon concentration. Alternativelyor additionally, the bath metal may include metals, or alloys of metals,such as Fe, Ni or related “active” bath metals.

In the preferred mode of operation, the carbon concentration in themolten metal is controlled so that it does not exceed its solubilitylimit. The resulting hydrogen-rich gas (H₂) stream, may also contain CO.The production of CO is generally proportional to the molar amount ofoxygen contained in the hydrocarbon feed. This gas stream and byproductsof N, S, Hg and other gaseous contaminants and entrained dust (if any)are then transferred to a second reactor (e.g., the “primary Fe bath”).

This latter bath, preferably has a highly oxidized metal (e.g., FeO)that can serve as the oxygen source to convert the gas streamoriginating from the first bath (e.g., the “primary Sn bath”) toprimarily CO₂, SO₃, N₂ and H₂ while providing an upper “secondary Febath” with partially oxidized metal substantially free of carbon andother impurities. Separation of the off gasses from the first moltenmetal zone (e.g., primary Sn bath) is achieved by removing the Hg andSO₃ in successive condensers and the H₂ from the CO₂ by pressure swingabsorption (PSA).

S+3FeO=SO₃+3Fe

A portion of the first molten metal bath, or primary Sn bath, can bereversibly transferred to an adjoined upper metal containing bath (the“secondary Sn bath”) by operating on the basis of differential pressurebetween reactor baths in vertical alignment. The pressure differentialrequired for transfer is a function of the specific gravity of the bathmetal and the relationship to the lift height (inches of column).Varying the pressure differential between the lower and upper metal bathcan control rate of transfer. Metal transfer can also be controlled byreleasing or building pressure using, for example, the exit gas controlvalves and feedstock injection rates. The upper, or “secondary Sn bath,”is injected with steam to react with dissolved carbon producing CO+H₂ ina 1:1 molar ratio (syngas), or with hydrogen gas to form methane, asdescribed in more detail below.

C+H₂O=CO+H₂

In one embodiment, metal may be transferred from the upper bath to thelower bath, an operation that requires an alternating pressuredifferential. Regulating bath pressures between the reactors can alsofacilitate the transfer of gases from one reactor to another, e.g., byselecting a pressure drop. It is particularly useful to maintain therelative pressure in the first bath vessel (P1) greater than that in thelower or third bath vessel (P3 ) which is greater than that in upper orsecond bath vessel (P2). If the upper or second bath is alwaysmaintained at a lower pressure than the other three baths, then gaseousmaterials may always be transferred to upper bath one, in the order ofdecreasing bath pressure, without the need for intermittent gascompression.

It is particularly advantageous to produce a high purity, high pressure(supercritical) CO₂ gas stream. The primary costs associated with thecapital costs and the energy costs for gas compression can add up totwenty percent of the overall process expenditure. The fact that the CO₂gas stream exits the reactor under supercritical conditions can used togreat advantage for direct CO₂ pipeline injection for enhanced oilrecovery or to be sequestered into a saline aquifer because this wouldobviate the compression costs.

Another preferred operating mode of this process produces a pure methane(CH₄) stream by moving the highly oxidized liquid metal (Fe/FeO) in“primary lower Fe bath”, free from impurities, to an upper “secondary Febath” maintaining the pressure at about 200 bar by utilizing a pressuredifferential. Alternatively, the metal bath may comprise Pb, Sn or othermetals and alloys. The highly oxidized state of the lower “primary Febath” metal bath can be maintained by transferring the molten metalcontaining dissolved FeO gravimetrically from the adjoined upper bath ina continuous manner. Since the upper “secondary Fe bath” is basicallyfree from all carbon and other deleterious impurities (e.g. N, S, Hg)when it is injected with steam to further oxidize the metal, a pure H₂stream is produced. This pure H₂ stream can continuously be removed orin this

Fe+H₂O=FeO+H₂

application it can be injected into the carbon saturated upper liquidmetal bath (“secondary Sn bath”), that is maintained at a temperaturebelow about 800° F., to optimize production of pure CH₄.

C+2H₂=CH₄

It is also worthy of note that the stoichiometry of the direct reductionof atomic carbon for the production of methane requires 2H₂. This is adistinct advantage over conventional methods utilizing syngas (CO:H₂)over a Ni catalyst because this process must be operated in tandem witha water shift reaction (CO+H₂O=H₂+CO₂) and the methanation step requiresthe net consumption of 3H₂ with the formation of a water molecule.

There are other advantages to using a molten metal catalyst for theproduction of methane and related hydrocarbons. As is known in the art,most processes that can accomplish this type of atomic carbon reductionutilize of a metal catalyst adsorbed on a solid catalyst support. Suchmethods suffer the disadvantages of a greatly reduced surface arearelative to a molten metal catalyst. These types of catalytic surfacesoften require relatively high temperatures to affect the desired yieldof reduction and as a consequence of accompanying high exothermicity maysuffer “hot spots” with catalyst meltdown.

The method of the present invention is aimed at the relatively low costproduction of large quantities of high quality, high pressure gasstreams of methane, syngas and hydrogen. The high cost associated withavailable production methods for such high value gas streamsdemonstrates the need for more economical and environmentally friendlymethodologies. According to the present invention, high volumes of highpurity, high pressure gas streams can be economically generated.

The present invention generally relates to a method for producing andrecovering gaseous products for further transfer and remediation in aseries of conjoined metal baths, by chemically oxidizing or reducing thecarbonaceous component of the hydrocarbon feedstock in a molten metalbath. The composition of the hydrocarbon may derive from coal sourcessuch as Illinois No. 6 coal, petroleum coke, oils such as No. 6 fueloil, biomass and biomass blends or waste hydrocarbon sources with asufficient BTU value to be economical.

The molten metal bath may preferably be comprised of iron(Fe) or tin(Sn)or an alloy of these two metals. A particular metal alloy may derivefrom admixture of two or more metals or by the introduction of an oxideof one or more such metals (e.g. Fe₂O₃ or SnO₂) to the molten metal bathfor in situ reduction of the metal oxide to its respective metal withinthe bath by the action of dissolved carbon or CO or the like. The liquidmetal bath may also contain one or more metals derived from the list ofreactive metals that may include antimony (Sb), Cobalt (Co) germanium(Ge), indium (In), molybdenum (Mo), tungsten (W), lead (Pb) and zinc(Zn). As is well known in the art, these so-called “reactive metals” andtheir respective metal oxides have free energies of oxidation, at thetemperature and partial pressure of oxygen of the bath, that is greaterthan that for the conversion of carbon to carbon monoxide. Contrariwise,the metal bath may also include at least one of the metals taken fromthe list of relatively “unreactive metals” that may include bismuth(Bi), cadmium (Cd), copper (Cu), gold (Au), iridium (Ir), mercury (Hg),nickel (Ni), osmium (Os), platinum (Pt), rhenium (Re), rhodium (Rh),ruthenium (Ru), selenium (Se) and tellurium (Te). The latter list ofpotential bath metals lie above the “CO line” (2C+O₂=2CO) represented bya plot of the bath temperature versus the free energy of the partialpressure of oxygen (p_(O2)) for this series of metals. Such relatively“unreactive metals” under the conditions of our method should have anoxygen partial pressure (p_(O2)) in equilibrium with the metals andmetal oxides that is relatively high. Such metals can serve to restrictthe effective concentration of the active metal within the metal baththat is actually involved in the metal oxidation step.

The series of metal baths illustrated in the FIG. 3, is one embodimentof an overall reactor suitable for practicing the method of theinvention. While we do not wish to be restricted to any one design for amolten metal bath reactor, there are several design elements unique tothe multiple liquid metal bath reactor described in the FIG. 3. The hightemperature liquid metal bath containment vessel is designed to operateat high pressures in excess of 200 bar. A Provisional Patent ApplicationNo. 61/025,684 has been filed that more specifically describes thisreactor. The molten metal bath itself is surrounded by a high pressurecontainment vessel that is maintained at a pressure above that of themetal bath. This system is novel to the existing art for suchgasification systems because the structural integrity of the containmentvessel for the metal bath, while being exposed to the high operatingtemperatures of the metal within the bath, is not directly exposed tothe high operating temperatures at 200 bar pressure and this is anadvantage. The outer gas zone also suffices as a temperature moderatorbecause the outer steel pressure vessel is not subject to the hightemperatures within the liquid metal bath. This is a distinct advantageof this invention in design and safety of operation because aselaborated in the teachings of Kindig et. al. (U.S. Publication No.20020124466) coal gasification is preferably operated at ambient or nearambient pressures, not to exceed 5 psi. When the unit is operated at anelevated pressure, substantial quantities of methane-containing productsare formed that can contaminant the hydrogen gas stream. The highpressures also offer advantages in residence time within the reactoritself to insure adequate steam residence time within the reactor. Butmore importantly, the off gas product streams exit the reactor atpressures only slightly reduced from the metal bath operating pressuresoften approaching 200 bar. This offers distinct economic advantages incapital costs associated with compressing the off gases in applicationswhere gaseous products such as syngas are required to be at highpressure.

Another novel aspect of this invention is the liquid metal transfersystem. While conventional wisdom dictates that the movement of metalwithin a liquid metal bath detracts from the cost effectiveness of aprocess, our invention operates on the basis of differential pressurebetween reactor baths in a vertical alignment. Since we are already at ahigh pressure within the reactor, the cost of pumping carbon saturatedmetal from a lower to a higher position does not add directly to thecost of the operation. Thus, accurate control of the metal transferrates at high pressure is a key advantage over prior art. Metal transferrates can be controlled by releasing or building pressure using the exitgas control valves and feedstock injection rates. Moving metal from alower bath to an upper bath requires a pressure difference greater thanthe pressure required to lift the metal and overcome resistance in metaltransfer piping. Mainly, the force of gravity overcoming metal transferpiping resistance accomplishes the return of molten metal, that islargely depleted of carbon, from the upper bath to the lower bath. Metaltransfer systems can be used with or without transfer piping controlvalves depending on the feedstock and the metal catalyst used.

Adequate control of the rate of liquid metal flow, as well as, the gasflow during operation is another unique feature of this multiple bathreactor design. Thus, the flow of hot metal and gases within the reactoritself is inhibited by design by immersed bath static strippers. The useof such an intermediate interruption in flow is unique in that theliquid metal is diverted by the stripper affecting increased residencetime in the bath, while gas flow through the strippers provides reducedgas bubble size. The bath operating at high pressure in combination withthe reduced gas bubble size provides for a coalescent liquid metal bathsurface verses the prior art having a turbulent surface with splashingcaused by large gas bubbles breaking the surface. The quiescent surfacealso minimizes contamination of the product gas and splashing of metaland slag on the walls of the vessel.

The method of introduction of the feedstock into the reactor is also offundamental importance. Although we do not wish to be restricted to anyone type of feed system, in the preferred mode of this invention thematerial should be feed directly into the molten metal bath. Thisinsures that the rate of decomposition and hence the rise in pressure iscontrolled in a measurable manner. The preferred manner of feedintroduction of solids, rendered in a particulate manner of fairlyuniform size, may be introduced by auger extrusion either as a solid orin slurry form. Gases and liquids may be introduced in a wellestablished fashion as is known in the art.

This multiple liquid metal bath reactor system can be used effectivelyin a mode using two or more multiple bath reactors. A preferredembodiment is the use of two dual bath reactors or a quad configurationfor direct production of synthetic natural gas (SNG) or pure methane.Referring to the FIG. 3, solid hydrocarbon feedstocks (including but notlimited to coal or petroleum coke) are fed into the lower Sn bath 2 ofthe reactor at a rate that generates a controlled pressure of 150-200bar via inlet port 1. Upon thermal dissociation of the hydrocarbonfeedstock, moisture present in the feedstock oxidizes dissolved carbonto CO gas and H₂. Over-oxidation of the carbon results in the formationof CO₂. Bath conditions can be selected such that the bath, saturated indissolved carbon, will result in the endothermic reduction back to CO.

CO₂+C=2CO

The CO and additional offgases from lower bath 2 will generally containcontaminants, including H₂S, N₂ and Hg. This gas stream is fed into thelower iron (Fe/FeO) bath 13. via gas transfer stream 6 and inlet port12. The lower iron bath 13 is rich in FeO and converts the combined gasstream from 2 to primarily CO₂, SO₃, and H₂ after condensing out themercury while providing partially oxidized iron metal free of carbon,which can then be transferred to the upper iron bath 18 via transferline 15.

Water derived from the feedstock in its conversion to CO is oxidizedexothermically to CO₂ providing thermal energy to the lower Fe bath.Thus, water present in the feedstock is not necessarily a deleteriousproblem, as compared to prior art processes. Thus, in one embodiment,the feedstock may optionally contain water, e.g., in amounts up to about70% by weight, preferably up to 50% by weight, more preferably up toabout 20% by weight. In some embodiments, water or steam can be injectedwith the feedstock or separately into the bath 2 exactly for thispurpose. For example, steam can be added in an amount of at least 60% byweight of carbon in the feedstock, preferably between about 10 and 40%by weight. The amount of water added is related to the amount of waterinitially present in the feedstock to arrive at a total water content ofup to about 70% by weight of carbon in the feedstock. In otherembodiments, water can be injected into the bath for steam to begenerated in situ.

Lower bath 2 can optionally act as a scrubber for the hydrocarbonfeedstock, thereby providing carbon-saturated Sn metal or a Sn metalcomposition which contains significant amounts of carbon. Preferably,the Sn metal composition is substantially free of impurities. The Snmetal composition can be transferred by differential pressure ormechanically to upper Sn bath 8 via transfer line 5. The upper iron bath18 is preferably substantially free of dissolved carbon. Steam isinjected into the bath 18 via inlet 17 to further oxidize the Fe metaland produce FeO and pure H₂.

This highly purified, high-pressure H₂ gas stream exits from point 21and can be recovered in whole or in part and/or injected through valve11 into the carbon saturated upper liquid Sn metal bath 8.Highly-purified, high-pressure CH₄ can be produced by the reduction ofdissolved carbon in the upper liquid Sn metal bath 8. The Fe/FeO metalstream in upper Fe bath 18 can be transferred to lower Fe bath 13 viatransfer line 19 for reduction by the off gas stream from lower Sn bath2. A high pressure (e.g., between about 150-200 bar) is maintainedthroughout the system (e.g., head spaces 4, 10, 14 and 20) to optimizepurity and pressure of the product gas streams. The use of such a seriesof conjoined metal baths represents a distinct departure from knownmethods and not only provides a system that does not requireconventional gas scrubbing and disposal of solid wastes, butadditionally, allows the conversion of these entrained impurities tosaleable high pressure off gas streams (CO₂, SO₃ and H₂).

Slag, as needed, is removed from lower Sn bath 2 through slag exit point3. Hydrocarbon feed, e.g. a feed with a high ash content, may be passedthrough the lower primary molten metal bath 2 to preferentially separateout a portion of the dust from the hydrocarbon feed in the slag layer.As a portion of the dust is entrained in the slag layer, theconcentration of dust in the head space 4 and thereby removed in the gasstream via exhaust port 6 can be reduced. The slag preferably removes atleast a portion of the dust generated from the hydrocarbon feedstock,this is particularly true where the hydrocarbon feedstock possesses ahigh ash content.

In a preferred embodiment of the process of the invention, sulfur fromthe hydrocarbon feed can also be removed and/or recovered from theprocess. The SO₃ produced can be removed from gas stream 16 bycondensation. Quenching with water produces sulfuric acid (H₂SO₄) havingpurities up to and above 90%; a byproduct of considerable economicvalue.

The molten metal reactor can include both sets of conjoined reactors, asshown in the FIG. 3 or can include one conjoined reactor, such as thetwo such molten metal baths aligned vertically as shown in the FIG. 3(baths 2 and 8). In this embodiment the off gases from the lower metalbath can be scrubbed in a conventional manner to remove impurities fromthe syngas produced therein. This embodiment preserves the distinctadvantages of maintaining high pressure and reversible metalcirculation, thereby insuring an upper bath substantially free fromfeedstock impurities (e.g. S and Hg) that exit the lower bath as offgases and dust that exits with the slag. For example, operation in thismode offers distinct advantages in the production of high purity, highpressure hydrogen gas streams from the moisture induced oxidation of Fe,Sn or comparable metal alloys. In this embodiment of the invention whereonly two metal baths, vertically juxtaposed are involved, sulfur fromthe hydrocarbon feed can also be allowed to build up to in the lowermolten metal bath, react to form hydrogen sulfide and be removed fromthe off gases at high pressure by conventional means such as causticscrubbing, etc.

The initial liquid state of the metal bath can achieved by plasma torch,electric arc or most preferably by induction coil heating. The desiredtemperature of the iron bath (up to 3000° F.) can be maintained byinduction currents flowing through coils or loops or by the exothermicoxidation of Fe by injected oxygen. The temperature of lower Fe bath 13can be increased by the oxidation of CO to CO₂.

Suitable means to inject a predetermined amount of steam into bath 18through injection point 21 includes simple steam lances. Steam injectionis one means that can be used to effectively control the temperature ofthe process due to the reaction of water with iron. Since the iron andtin baths must be operated at substantially different temperatures, itis necessary to pass the H₂ gas stream exiting gas valve 21 attemperatures approaching 2000° F. through a heat exchanger prior tointroducing this H₂ reductant stream into upper Sn bath 8 thoughentrance valve 11 where temperatures should not exceed 900° F. However,the latent heat from this temperature reduction can advantageously beused for the production of steam used in the accompanying waterreduction step. Additionally, the transfer of thermal energy from, theFe bath, which basically operates under exothermic conditions, canameliorate the heat balance in the Sn baths where the endothermicoxidation of carbon by water tends to deplete the bath temperature.

Illustrations Illustration I

High purity, high pressure methane, (CH₄) was produced from petroleumcoke feedstock containing 79.0% carbon, 3.6% hydrogen, 6.7% sulfur and9.0% water. The finely ground petroleum coke is bottom injected throughinjection point 1 into a 950° F. molten Sn bath 2 at a rate of 1 lb/sec.Thermal decomposition of the hydrocarbon feedstock results in a constantpressure of 150 bar in lower bath gas zone 4. Molten Sn/C is transferredfrom lower Sn bath 2 to upper Sn bath 8 via transfer line 9 bymaintaining a reduced pressure of 135 bar in upper gas space 10. Slagremoval as necessary is maintained through slag removal system 3. Anadditional 0.39 lb/sec of water is injected through injection point 1into bath 2 for the oxidation of C to CO in lower Sn bath 2.

The combined off gases (CO, H₂, H₂S, Hg and N₂) transfer continuouslythrough gas transfer control valve 6 through injection point 12 into a2850° F. molten Fe/FeO bottom bath 13. The CO is oxidized, in whole orin part, to CO₂ by the action of iron oxides (FeO, Fe₂O₃ etc.) in lowerbath 13 and, thereby, provides thermal energy to, in whole or in part,maintain the bath temperature. The off gases from lower Fe/FeO bath 13at 149 bar exit through gas valve 16 for further processing.

Molten Fe/FeO is transferred by differential pressure from lower Fe/FeObath 13 to upper Fe/FeO bath 18. The upper gas space 20 is maintained at141 bar. Steam (0.60 lb/sec) is injected into the upper Fe/FeO bath 18,which is maintained at 2850° F. A high pressure (141 bar) stream of pureH₂ is produced and exits through gas valve 21 (0.07 lb/sec). The H₂ gasenters a heat exchanger at an inlet temperature of 1900° F. with the H₂gas at a rate of (0.09 lb/sec) separated from the processed gas streamexiting through gas valve 16. After heat reduction to 750° F., the H₂ istransferred through injection point 7 at a rate of 0.09 lb/sec into acarbon saturated molten Sn bath 8. The dissolved C is reduced by the H₂gas, producing CH₄ gas into gas zone 10. The gas in zone 10 has atemperature of 750° F. and exits the reactor through gas valve 11.

The high purity high pressure CH₄ gas stream is produced continuously ata rate of 0.62 lb/sec. Saleable products are produced from the remainingoff gases; 0.17 lb/sec of SO₃ and 1.18 lb/sec of CO₂.

The Sn in bath 8 is recycled back to Sn bath 2. Likewise, the Fe bath inbath 18 is recycled to the Fe bath 13. The method is preferablyperformed in a continuous fashion.

Illustration II

High purity, high pressure methane, (CH₄) is produced from 70%biomass/30% petcoke blended feedstock contained 55.5% carbon, 4.7%hydrogen, 2.2% sulfur, 9.7% water and 3.4% ash. The finely groundhydrocarbon feedstock is bottom injected through injection point 1 intoa 950° F. molten Sn bath 2 at a rate of 13 lb/sec. The hydrocarbonfeedstock is subjected to thermal decomposition. A constant pressure of150 bar in lower bath gas zone 4 is maintained. Molten Sn/C istransferred from the lower Sn bath 2 to the upper Sn bath 8 maintaininga reduced pressure of 135 bar in the upper gas space 10. Slag removal asnecessary is maintained through slag removal system 3. An additional0.02 lb/sec of water is injected through injection point 1 into bath 2for the oxidation of C to CO in lower Sn bath 2. The combined off gases(CO, H₂, H₂S, N₂) transfer continuously through gas transfer controlvalve 6 through injection point 12 into the 2850° F. molten Fe/FeObottom bath 13. The CO from both sources, feedstock and additionalwater, are oxidized to CO₂ by the action of iron oxides (FeO, Fe₂O₃etc.) in lower bath 13 to provide thermal energy to maintain the bathtemperature. The off gases from lower Fe/FeO bath 13 at 149 bar exitthrough gas valve 16 for further processing. Molten Fe/FeO istransferred by differential pressure from lower Fe/FeO bath 13 to upperFe/FeO bath 18 at 141 bar. Simultaneously, steam (5.3 lb/sec) isinjected into the upper Fe/FeO bath 18 maintained at 2850° F. producinga high pressure stream of pure H₂ gas that exits through gas valve 21(0.6 lb/sec) and enters a heat exchanger at a temperature of 1900° F.with the H₂ gas (0.8 lb/sec) separated from the processed gas streamexiting through gas valve 16. After heat reduction to 750° F., the H₂ istransferred through injection point 7 into carbon saturated molten Snbath 8. The dissolved C (4.0 lbs/sec) is reduced by the H₂ gas producingCH₄ gas evolving into gas zone 10 that is maintained at a temperature of750° F. and exits the reactor through gas valve 11.

The high purity high pressure CH₄ gas stream is produced continuously ata rate of 5.3 lb/sec. Saleable products are produced from the remainingoff gases; 0.7 lb/sec of SO₃ and 11.7 lb/sec of CO₂.

Illustration III

High purity, high pressure methane, (CH₄) is produced from Illinois No.6 coal feedstock contained 60.5% carbon, 4.1% hydrogen, 2.6% sulfur,13.6% water and 9.9% ash. The finely ground coal is bottom injectedthrough injection point 1 into a 950° F. molten Sn bath 2 at a rate of14.2 lb/sec. Thermal decomposition of the hydrocarbon feedstock resultsin a constant pressure of 150 bar in lower bath gas zone 4. Molten Sn/Cis transferred from lower Sn bath 2 to upper Sn bath 8 maintaining areduced pressure of 135 bar in upper gas space 10. Slag removal asnecessary is maintained through slag removal system 3. An additional 2.1lb/sec of water is injected through injection point 1 into bath 2 forthe oxidation of C to CO in lower Sn bath 2. The combined off gases (CO,H₂, H₂S, N₂) transfer continuously through gas transfer control valve 6through injection point 12 into the 2850° F. molten Fe/FeO bottom bath13. The CO from both sources, feedstock and additional water, areoxidized to CO₂ by the action of iron oxides (FeO, Fe₂O₃ etc.) in lowerbath 13 to provide thermal energy to maintain the bath temperature. Theoff gases from lower Fe/FeO bath 13 at 149 bar exit through gas valve 16for further processing. Molten Fe/FeO is transferred by differentialpressure from lower Fe/FeO bath 13 to upper Fe/FeO bath 18 at 141 bar.Simultaneously, steam (5.9 lb/sec) is injected into the upper Fe/FeObath 18 maintained at 2850° F. producing a high pressure stream of pureH₂ gas that exits through gas valve 21 (0.7 lb/sec) and enters a heatexchanger at a temperature of 1900° F. with the H₂ gas (1.0 lb/sec)separated from the processed gas stream exiting through gas valve 16.After heat reduction to 750° F., the H₂ is transferred through injectionpoint 7 into carbon saturated molten Sn bath 8. The dissolved C isreduced by the H₂ gas producing CH₄ gas evolving into gas zone 10 thatis maintained at a temperature of 750° F. and exits the reactor throughgas valve 11.

The high purity high pressure CH₄ gas stream is produced continuously ata rate of 6.7 lb/sec. The saleable products produced from the remainingoff gases (0.9 lb/sec of SO₃) are recovered as H₂SO₄ and 13.0 lb/sec ofCO₂ is transferred .as a high purity, high pressure gas stream.

Illustration IV

High purity, high pressure methane, (CH₄) is produced from No. 6 FuelOil feedstock containing 85.0% carbon, 9.7% hydrogen, 2.1% sulfur and0.7% water. The feedstock is bottom injected through injection point 1into a 950° F. molten Sn bath 2 at a rate of 8 lb/sec. Thermaldecomposition of the hydrocarbon feedstock results in a constantpressure of 150 bar in lower bath gas zone 4. Molten Sn/C is transferredfrom lower Sn bath 2 to upper Sn bath 8 maintaining a reduced pressureof 135 bar in upper gas space 10. Slag removal as necessary ismaintained through slag removal system 3.

An additional 3.2 lb/sec of water is injected through injection point 1into bath 2 for the oxidation of C to CO in lower Sn bath 2. Thecombined off gases (CO, H₂, H₂S, N₂) transfer continuously through gastransfer control valve 6 through injection point 12 into the 2850° F.molten Fe/FeO bottom bath 13. The CO from both sources, feedstock andadditional water, are oxidized to CO₂ by the action of iron oxides (FeO,Fe₂O₃ etc.) in lower bath 13 to provide thermal energy to maintain thebath temperature. The off gases from lower Fe/FeO bath 13 at 149 barexit through gas valve 16 for further processing. Molten Fe/FeO istransferred by differential pressure from lower Fe/FeO bath 13 to upperFe/FeO bath 18 at 141 bar. Simultaneously, steam (3.6 lb/sec) isinjected into the upper Fe/FeO bath 18 maintained at 2850° F. producinga high pressure stream of pure H₂ gas that exits through gas valve 21(0.4 lb/sec) and enters a heat exchanger at a temperature of 1900° F.with the H₂ gas (1.1 lb/sec) separated from the processed gas streamexiting through gas valve 16. After heat reduction to 750° F., the H₂ istransferred through injection point 7 into carbon saturated molten Snbath 8. The dissolved C is reduced by the H₂ gas producing CH₄ gasevolving into gas zone 10 that is maintained at a temperature of 750° F.and exits the reactor through gas valve 11.

The high purity high pressure CH₄ gas stream is produced continuously ata rate of 6.1 lb/sec. Saleable products are produced from the remainingoff gases; 0.4 lb/sec of SO₃ and 8.1 lb/sec of CO₂.

Illustration V

High purity, high pressure syngas, (CO/H₂) is produced from Pittsburg 8coal feedstock containing 73.2% carbon, 4.5% hydrogen, 5.2% oxygen, 2.4%sulfur, 6.1% water and 7.0% ash. The finely ground feedstock is bottominjected through injection point 1 into a 950° F. molten Sn bath 2 at arate of 15 lb/sec. Thermal decomposition of the hydrocarbon feedstockresults in a constant pressure of 150 bar in lower bath gas zone 4.Molten Sn/C containing dissolved carbon is transferred from lower Snbath 2 to upper Sn bath 8 maintaining a reduced pressure of 135 bar inupper gas space 10. Slag removal as necessary is maintained through slagremoval system 3. An additional 5.3 lb/sec of water and 8.3 lb/sec ofoxygen gas is injected through injection point 7 into bath 8 for theoxidation of C (9.8 lb/sec) to CO. The combined off gases (CO, H₂, H₂S,N₂) transfer continuously through gas transfer control valve 6 throughinjection point 12 into the 2850° F. molten Fe/FeO bottom bath 13. TheCO from the lower bath (2.8 lb/sec), is oxidized to CO₂ by the action ofiron oxides (FeO, Fe₂O₃ etc.) in lower bath 13 to provide thermal energyto maintain the bath temperature. The off gases from lower Fe/FeO bath13 at 150 bar exit through gas valve 16 for further processing. MoltenFe/FeO is transferred by differential pressure from lower Fe/FeO bath 13to upper Fe/FeO bath 18 at 141 bar. Simultaneously, steam (2.4 lb/sec)is injected into the upper Fe/FeO bath 18 maintained at 2850° F.producing a high pressure stream of pure H₂ gas that exits through gasvalve 21 (0.3 lb/sec).

The high purity high pressure syngas stream is produced continuously ata rate of 22.8 lb/sec of CO and 0.6 lb/sec of H2 gas and exited throughgas transfer valve 11 where it is combined with 1.2 lb/sec of H₂ gasfrom gas transfer valve 21 and the purified H₂ gas stream produce fromgas transfer valve 16. The saleable products produced from the remainingoff gases (0.9 lb/sec of SO₃) are recovered as H₂SO₄ and 4.4 lb/sec ofCO₂ and is transferred as a high purity, high pressure gas stream.

Illustration VI

High purity, high pressure hydrogen (H₂) gas is produced from petroleumcoke feedstock containing 79.0% carbon, 3.6% hydrogen, 6.7% sulfur and9.0% water and 0.4% ash. The finely ground feedstock (15 lb/sec) and10.5 lb/sec of oxygen is bottom injected through injection point 1 intoa 2850° F. molten Fe bath 2. Thermal decomposition of the hydrocarbonfeedstock results in a constant pressure of 149 bar in lower bath gaszone 4. Molten Fe/FeO is transferred from lower Fe bath 2 to upper Febath 8 maintaining a reduced pressure of 141 bar in upper gas space 10.Slag removal as necessary is maintained through slag removal system 3.An additional 24.0 lb/sec of steam is injected through injection point 7into bath 8 for the oxidation of Fe to FeO+H₂.

The high purity high pressure H₂ gas stream is produced continuously ata rate of 2.7 lb/sec and exited through gas transfer valve 11 where itis combined with 0.7 lb/sec of purified H₂ gas stream produced from gastransfer valve 16. The saleable products produced from the remaining offgases from gas transfer valve 16 after processing are 0.9 lb/sec of SO₃recovered as H₂SO₄ and 43.4 lb/sec of CO₂ as a high purity, highpressure gas stream.

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

1. A reactor system capable of withstanding high temperatures and highpressures comprising: a. a first bath vessel capable of containing abath having a bath temperature, T1, and a bath vessel pressure, P1, andb. a reactor housing characterized by a housing temperature, T10,Wherein the first bath vessel is contained within the housing and havinga gas zone having a gas zone pressure, P10, disposed therebetween andwherein P10 approximately the same as P1 and T10 is less than T1.
 2. Thereactor system of claim 1 further comprising a second bath vessel withinthe housing.
 3. The reactor system of claim 2, wherein each bath vesselis made of a material that has a tensile strength of at least 100,000psi and is capable of containing a molten metal.
 4. The reactor systemof claim 3, wherein each bath vessel comprises stainless steel orgraphite.
 5. The reactor system of claim 3, wherein each bath vesselcontains a molten metal.
 6. The reactor system of claim 4, wherein thesecond bath vessel is disposed above the first bath vessel.
 7. Thereactor system of claim 6, wherein the bath vessel pressure in thesecond bath vessel, P2, is lower than P1.
 8. The reactor system of claim7 further comprising a first conduit in fluid communication with thesecond bath vessel and first bath vessel, whereby the pressuredifference between P1 and P2 causes transfer of a molten metal residingin said first bath vessel to said second bath vessel.
 9. The reactorsystem of claim 8, wherein the first conduit comprises an inlet disposedin the lower half of the first bath vessel and an outlet disposed in theupper half of the second bath vessel.
 10. The reactor system of claim 9,wherein the first conduit comprises a first valve to control moltenmetal transfer.
 11. The reactor system of claim 9 further comprising asecond conduit in fluidcommunication with the second bath vessel andfirst bath vessel, whereby gravity causes transfer of a molten metalbath residing in said second bath vessel to said first bath vessel. 12.The reactor system of claim 11, wherein the second conduit comprises aninlet disposed in the lower half of the second bath vessel and an outletdisposed in the upper half of the first bath vessel.
 13. The reactorsystem of claim 12, wherein the second conduit comprises a second valveto control molten metal transfer.
 14. The reactor system of claim 12,wherein each bath vessel is characterized by at least one gas exhaustport, at least one steam inlet port, at least one feedstock inlet portand/or at least one gas inlet port.
 15. The reactor system of claim 14,wherein each inlet port is located below the surface of the molten metalin each bath vessel.
 16. The reactor system of claim 15 wherein at leastone inlet port comprises a tuyere.
 17. The reactor system of claim 13further comprising: a. a third bath vessel capable of containing amolten metal bath having a bath temperature, T3 and a bath pressure P3;b. a fourth bath vessel capable of containing a molten metal bath havinga bath temperature, T4 and a bath vessel pressure P4 disposed above saidthird bath vessel; c. a second reactor housing characterized by ahousing temperature, T11, wherein the third bath vessel is containedwithin the second reactor housing and having a gas zone having a gaszone pressure, P11, disposed therebetween and wherein P11 approximatelythe same as P3 and T11 is less than T3; d. a third conduit in fluidcommunication with the third bath vessel and fourth bath vessel, wherebythe pressure difference between P3 and P4 causes transfer of a moltenmetal residing in said third bath vessel to said fourth bath vessel andwherein the third conduit comprises an inlet disposed in the lower halfof the third bath vessel and an outlet disposed in the upper half of thefourth bath vessel; e. a fourth conduit in fluid communication with thethird bath vessel and fourth bath vessel, whereby gravity causestransfer of a molten metal bath residing in said fourth bath vessel tosaid third bath vessel; wherein the fourth conduit comprises an inletdisposed in the lower half of the fourth bath vessel and an outletdisposed in the upper half of the third bath vessel.
 18. The reactorsystem of claim 17, wherein each bath vessel is characterized by a headspace and the head space of the first bath vessel is in fluidcommunication with the molten metal bath of the third bath vessel; thehead space of the fourth bath vessel is in fluid communication with thesecond bath vessel.
 19. A reactor system comprising: a. a first bathvessel capable of containing a bath having a bath temperature, T1 and abath pressure P1; b. a second bath vessel capable of containing a bathhaving a bath temperature, T2 and a bath vessel pressure P2 disposedabove said first bath vessel; c. a first conduit in fluid communicationwith the first bath vessel and second bath vessel, whereby the pressuredifference between P2 and P1 causes transfer of a liquid residing insaid first bath vessel to said second bath vessel; and d. a secondconduit in fluid communication with the first bath vessel and secondbath vessel, whereby gravity causes transfer of a liquid residing insaid second bath vessel to said first bath vessel.
 20. The reactorsystem of claim 19, wherein the first and second bath vessels containthe liquid wherein the liquid is a molten metal.
 21. A process formaking a high purity methane gas comprising the steps of: a. Adding acarbon-containing feed stream into a first bath vessel containing afirst molten metal bath wherein the first bath vessel is maintained at apressure, P1, of at least 1 bar, preferably at least 100 bar, andproducing a first vessel gas stream comprising carbon monoxide andhydrogen sulfide; b. Removing the first vessel gas stream from the firstbath vessel and introducing the gas stream into a third bath vesselcontaining a third molten metal bath wherein the third bath vessel ismaintained at a third pressure, P3, of at least 1 bar, preferably atleast 100 bar, optionally adding an oxygen source, such as steam or anoxygen containing feed, and producing a third vessel gas streamcomprising hydrogen, SO₃ and carbon dioxide; c. Removing the thirdvessel gas stream from the third vessel, and optionally condensing theSO₃ therefrom and/or removing the carbon dioxide; thereby obtaining apurified hydrogen gas; d. Adding steam to a fourth bath vesselcontaining a fourth molten metal bath characterized by a low carboncontent, wherein the fourth bath vessel is maintained at a fourthpressure, P4 , of at least 1 bar, preferably at least 100 bar, therebyproducing purified hydrogen; e. Adding the gas streams produced by step(c) and/or (d) to second bath vessel containing a second molten metalbath maintained at a second pressure, P2, of at least 1 bar, preferablyat least 100 bar, and a temperature of less than about 800-1000 F,characterized by a high carbon content, thereby producing purifiedmethane.
 22. A process for making a high purity syngas comprising thesteps of: a. Adding a carbon-containing feed stream into a first bathvessel containing a first molten metal bath wherein the first bathvessel is maintained at a pressure, P1, of at least 1 bar, preferably atleast 100 bar, and producing a first vessel gas stream comprising carbonmonoxide and hydrogen sulfide; b. Removing the first vessel gas streamfrom the first bath vessel and introducing the gas stream into a thirdbath vessel containing a third molten metal bath wherein the third bathvessel is maintained at a third pressure, P3, of at least 1 bar,preferably at least 100 bar, optionally adding an oxygen source, such assteam or an oxygen containing feed, and producing a third vessel gasstream comprising hydrogen, SO₃ and carbon dioxide; c. Removing thethird vessel gas stream from the third vessel, and optionally condensingthe SO₃ therefrom and/or removing the carbon dioxide; thereby obtaininga purified hydrogen gas; d. Adding steam to a fourth bath vesselcontaining a fourth molten metal bath characterized by a low carboncontent, wherein the fourth bath vessel is maintained at a fourthpressure, P4, of at least 1 bar, preferably at least 100 bar, therebyproducing purified hydrogen; e. Adding oxygen gas to a second bathvessel containing a second molten metal bath maintained at a secondpressure, P2, of at least 1 bar, preferably at least 100 bar, and atemperature of less than about 1000 F, characterized by a high carboncontent, thereby producing purified carbon monoxide.
 23. The method ofclaim 21 using a reactor system as claimed in claim
 17. 24. A processfor making a high purity hydrogen gas comprising the steps of: a. Addinga carbon-containing feed stream into a first bath vessel containing afirst molten metal bath wherein the first bath vessel is maintained at apressure, P1, of at least 1 bar, preferably at least 100 bar, andproducing latent heat by the introduction of an oxygen source andmaintaining a metal oxide rich molten metal bath; b. Transferring themetal oxide rich molten metal bath to an upper second bath vessel;maintained at a second pressure, P2, of at least 1 bar, preferably atleast 100 bar, and a temperature greater than about 500 F; c. Addingsteam to the upper molten metal bath thereby producing a high purityhydrogen gas.
 25. The process of claim 24 using a reactor of claim 1.26. The process of claim 21, wherein one or more of the molten metalbaths comprise iron and/or tin, having suspended therein, iron.
 27. Aprocess for producing syngas (CO/H₂) and/or H₂ gas streams, orhigh-purity, high-pressure CH₄ and CO₂ gas streams are producedseparately and continuously by the introduction of feedstocks comprisinghydrocarbons such as coal into a multiple molten metal bath reactorproducing gas streams that are further processed in conjoined multiplemetal bath reactors.
 28. The process of using a reactor as set forth inclaim 1 to convert a carbon-containing feedstock to one or more H2, CH₄,CO or CO₂ gas streams from a hydrocarbon feedstock.
 29. The process ofclaim 21, wherein the hydrocarbon feedstock comprises a coal.
 30. Theprocess of claim 21, wherein the hydrocarbon feedstock comprisespetroleum coke, coal, lignite coal, oil shale, natural gas or biomass.31. The process of claim 21, wherein the hydrocarbon feedstock comprisesliquid or gaseous hydrocarbons.
 32. The process of claim 21, wherein thehydrocarbon feedstock comprises a waste material having a thermalcontent of at least about 4,000 BTU per pound.
 33. The process of claim21, claim 21, wherein the feedstock is added by auger extrusion, bottomor side injection or by steam-cooled top lance injection.
 34. Theprocess of claim 21, wherein the pressure in at least one bath vessel ismaintained at about 10 bar or more and/or less than about 600 bar,preferably between about 150-200 bar.
 35. The process of claim 21,wherein the reactor pressure is controlled by the hydrocarbon feedstockaddition rate.
 36. The process of claim 21, wherein the molten metalbath is transferred between said first bath vessel and said second bathvessel and/or between said third bath vessel and said fourth bath vesselby maintaining a pressure differential greater than the pressurerequired to lift the metal and overcome resistance in metal transferpiping in a vertical and/or a diagonal direction.
 37. The process ofclaim 21, further comprising the step of extracting the Hg from a gas.38. The process of claim 21 further comprising the step of extractingSO₃by quenching with water to produce H₂SO₄.
 39. The process of claim 21further comprising the step of separating H₂ and CO₂ in the gas streamexiting the third bath vessel.
 40. The process of claim 21 furthercomprising the step of forming a slag layer by addition of a flux, suchas one or more oxides of Ca, Fe, K, Mg, Na, Si, Sn, and Ti.
 41. Theprocess of claim 21 comprising the maintenance of relative pressuressuch that P1 is greater than P3, and P3 is greater than P4 and P4 isgreater than P2, thereby allowing transfer of gaseous materials betweenthe bath vessels in the absence of gas compression.
 42. A method ofclaim 21, wherein the bath metal in the first two vertically orhorizontally aligned baths is an alloy of two or more metals comprisingmetals of sufficient oxidation potential to reduce water and the secondset of vertically or horizontally aligned metal baths comprises an alloyof two or more metals taken from the list of reactive metals thatincludes antimony (Sb), Cobalt (Co) germanium (Ge), indium (In),molybdenum (Mo), lead (Pb) tungsten (W) and zinc (Zn) or other metals.43. A method of claim 21, wherein the bath metal in the first twovertically aligned baths is an alloy of two or more metals wherein atleast one of the metals is a less reactive metal that will not reducewater under the bath conditions and the second set of vertically alignedmetal baths comprises an alloy of two or more metals where at least oneof the metals is taken from the list of relatively unreactive metalsthat includes bismuth (Bi), cadmium (Cd), copper (Cu), gold (Au),iridium (Ir), mercury (Hg), nickel (Ni), osmium (Os), platinum (Pt),rhenium (Re), rhodium (Rh), ruthenium (Ru), selenium (Se) and tellurium(Te).